"The complex codes have been created by a GCHQ team of top mathematicians," a spokeswoman for the agency said.

"They set a high bar for recruiting curious, tenacious and creative candidates who have the intellectual ability, though not necessarily the practical experience or qualifications, to join GCHQ and support the government's national cyber security agenda."

"The 21st century is confronting us with online threats that are difficult and dangerous, so we want employees who have evolved with the ever-changing digital world and therefore have the right skills to combat these challenges," she said.

"It's a puzzle but it's also a serious test – the jobs on offer here are vital to protecting national security."

Salaries for successful applicants range from £26,000 ($44,000) to £60,000.

How would you go about solving the puzzle? Leave your suggestions in the comments.

Fairfax Media

65 comments

I think I got it. The code says..."We've had just about enough of the Royals here in UK. Please save us".

QQ and EE have to represent, one or the other, english ee and oo: those are the only double vowels in english. The other double letters could be consonants, of which there are a number doubled(skip h, mostly f, j,k,q,v, w z).

Commenter

John

Location

Coffs Harbour

Date and time

September 12, 2013, 4:56PM

lol :)

Commenter

Meh1

Date and time

September 12, 2013, 5:43PM

i thought it said ' Thee only thing worse than the Australian cricket side, is their union side'

Commenter

micko

Date and time

September 12, 2013, 8:17PM

On the face of it, it would appear to be (at the first level) a substitution cipher. So letter frequency would be the first bit of info to use. If it is Englsih then it looks like q is e or t. I cant be bothered doing the rest for the people who killed Alan Turing. I will rather do the Friday DA.

Commenter

Odobenus

Location

Bankstwon

Date and time

September 12, 2013, 3:00PM

Did you use a substitution cypher to hide your location from readers? I'd too like to show off my code-cracking ability - by solving your riddle - but 'I can't be bothered.'

Commenter

Crack the basics first

Location

Sdyney

Date and time

September 12, 2013, 4:38PM

Surely not. That is boy scout stuff.

Commenter

John

Date and time

September 12, 2013, 8:49PM

A very stiff drink, for a start...

Commenter

tk

Date and time

September 12, 2013, 3:03PM

The first step to getting a job with GCHQ is probably to have more discretion than to post the puzzle answers in a public forum.

For extra credit, instead of sending in your answers, post them somewhere secret where GCHQ will intercept them.